Production tubing hydraulic release mechanism and method of use
A release mechanism for removing a subsurface safety control valve from a production string in a well bore is mounted below the safety valve in operational engagement with the safety valve and the production string. The release mechanism has a two-part construction, with the upper part being normally locked to the lower part and released from the lower part when changing of the safety valve is required.
1. A release device for releasing a portion of a well production string below a subsurface safety valve installed in the well production string, the device comprising:
a hollow housing having an upper portion and a lower portion fitted at least in part within the upper portion;
a means for connecting said housing below the subsurface safety valve in line with the production string;
a seal assembly mounted in the upper portion of said housing;
a locking means positioned in the upper portion of said housing for releasably locking the lower portion of the housing to the upper portion of the housing, said locking means comprising a latching assembly releasably engaging the lower portion and a locking assembly for retaining said latching assembly in a normally locked position with said lower portion, wherein said locking assembly comprises a transverse plate mounted for slidable movement in the upper portion, said transverse plate allowing the seal assembly to extend therethrough, and wherein said
latching assembly comprises a ring-shaped body, a plurality of legs extending downwardly from said ring-shaped body, each of said legs carrying a latching member;
a means for securing the lower portion of the housing to the production string below said upper portion;
a first opening formed in the upper portion of the housing for communication with a source of power above said subsurface safety valve for retaining said locking means in a locked position;
a second opening formed in the upper portion of the housing for communication with a source of power above said subsurface safety valve for releasing said locking means and allowing the portion of the production string above the subsurface safety valve to be removed from a well bore, while retaining the lower portion in the well bore.
2. The apparatus of claim 1 , wherein said locking assembly further comprises a plurality of locking members secured to the transverse plate and extending downwardly therefrom, said locking members normally retaining said latching members in engagement with the lower portion.
3. A release device for releasing a portion of a well production string below a subsurface safety valve installed in the well production string, the device comprising:
a hollow housing having an upper portion and a lower portion fitted at least in part within the upper portion;
a means for connecting said housing below the subsurface safety valve in line with the production string;
a seal assembly mounted in the upper portion of said housing, said seal assembly comprising an elongated mandrel carrying a plurality of sealing elements on an exterior surface thereof;
a locking means positioned in the upper portion of said housing for releasable locking the lower portion of the housing to the upper portion of the housing;
a means for securing the lower portion of the housing to the production string below said upper portion;
a first opening formed in the upper portion of the housing for communication with a source of power above said subsurface safety valve for retaining said locking means in a locked position;
a second opening formed in the upper portion of the housing for communication with a source of power above said subsurface safety valve for releasing said locking means and allowing the portion of the production string above the subsurface safety valve to be removed from a well bore, while retaining the lower portion in the well bore, and wherein said lower portion has an elongated tubular member mounted in the lower portion, and wherein said mandrel is configured for fitting in the tubular member.
4. The apparatus of claim 3 , wherein said mandrel comprises a beveled lower part to facilitate positioning of the seal assembly in the tubular member.
5. A method of taking a subsurface safety valve out of surface, said subsurface safety valve being mounted in a production string in a well bore, the method comprising the steps:
providing a housing comprising an upper portion and a lower portion fitted at lease in part in the upper portion and positioning said housing in the well bore in line with the production string and the subsurface safety valve;
providing a tubular member extending through said lower portion and connecting said tubular member to the production string below said housing;
securing the upper portion to the production string below said subsurface safety valve;
normally retaining the upper portion in a locked position with the lower portion;
securing the lower portion of the housing to the production string below said upper portion;
providing a first opening in the upper portion of the housing and establishing communication with a source of power above said subsurface safety valve for retaining said upper portion in a locked position;
providing a second opening in the upper portion of the housing and establishing communication with a source of power above said subsurface safety valve for releasing said locking means;
delivering a release power to the upper portion through said second opening, thereby causing said upper portion to be released from said lower portion and allowing a portion of the production string above the subsurface safety valve to be removed from a well bore, while retaining the lower portion in the well bore.
6. The method of claim 5 , further comprising the step of providing a seal assembly in the upper portion and releasably engaging the seal assembly with the tubular member.
7. The method of claim 6 , further comprising the step of providing a latching assembly in the upper portion and releasably engaging the lower portion with said latching assembly.
8. The method of claim 7 , further comprising a step of providing a locking assembly for retaining said latching assembly in a normally locked position with said lower portion.
9. The method of claim 8 , wherein said lower portion comprises a generally cylindrical body having an upper part, a lower part and a reduced diameter middle part, and wherein said latching assembly is configured for releasably engaging the middle part of the lower portion.
10. The method of claim 8 , wherein said locking assembly comprises a transverse plate mounted for slidable movement in the upper portion, said transverse plate allowing the seal assembly to extend therethrough.
11. The method of claim 10 , wherein said locking assembly further comprises a plurality of locking members secured to the transverse plate and extending downwardly therefrom, said locking members normally retaining said latching members in engagement with the lower portion.
12. The method of claim 7 , wherein said latching assembly comprises a ring-shaped body, a plurality of legs extending downwardly from said ring-shaped body, each of said legs carrying a latching member.